As I approach the age of 40, i've noticed having problems with my hip alignment. A friend who is a physical therapist advised me against keeping my wallet in my back pocket. Well, since all of my other pockets are full, i don't really have a choice...so I started thinking about what i could carry in the left rear pocket to balance myself out, that would also be useful. I found that a dollar store rain poncho and one of those cheap nylon drawstring bags folded up are pretty much an exact match for the thickness of my wallet. It is amazing how many times that little drawstring bag has come in handy. I've used it at the grocery store a few times, I've used it at work several times now when i have a bunch of small stuff i needed to transport. I went to someone's house the other day to pick up their PC to clean up, and they asked me if i would take some other old PC accessories to recycle. i pulled out my bag and stuffed it full of old random cables, webcams, mice, etc and it was super handy. I highly recommend adding one of these to your EDC.